Method and apparatus for providing long term protection from intrusion by insects and other cold blooded animals

ABSTRACT

Controlled release devices are shaped and placed in locations through which insects and/or other cold blooded animals generally enter an area or a structure sought to be protected. The controlled release devices include a polymeric matrix and a pesticide contained in the matrix. The pesticide is gradually released out of the matrix to the surface of the device. The pesticide on the surface of the device kills the intruding insects or other cold blooded animals that come in contact with the pesticide. In addition, if the device is in contact with a permeable structure or object, the pesticide released onto the surface of the device is absorbed by such permeable structure or object to provide a barrier to entry by the insects and/or other cold blooded animals.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a Continuation-in-Part of U.S. patent application, Ser. No. 08/348,774 filed on Dec. 1, 1994, which is a continuation of U.S. patent application, Ser. No. 08/117,877 filed on Sep. 7, 1993, which is a continuation of U.S. patent application, Ser. No. 07/893,970 filed on Jun. 4, 1992, which is a continuation of U.S. patent application, Ser. No. 07/401,955 filed on Sep. 1, 1989, which is a continuation-in-part of U.S. patent application, Ser. No. 555,113 filed on Nov. 23, 1983, which is a continuation-in-part of U.S. patent application, Ser. Nos. 06/314,809 and 06/314,810, both filed on Oct. 26, 1981.

BACKGROUND OF THE INVENTION

[0002] This invention relates to methods and devices for preventing insects and other cold blooded animals from intruding into certain areas or certain structures. In particular, it relates to providing long term protection against such intrusions.

[0003] Insects and other cold blooded animals need to be kept out certain areas and/or certain structures. Their intrusions into such areas or structures can create problems ranging in severity from merely a nuisance to those having dire consequences. For example, fire ants have to be kept out of electrical power distribution enclosures. Their intrusion into such enclosures can cause damage or even destruction of the electrical power distribution system. Fire ants also create a nuisance or damage by entering into buildings through cracks in the walls. In addition, the existence of fire ants in a quarantine zone can cause considerable expense to the plant nurseries in such zone. The plants which are shipped outside the zone must be certified to be ant free. The procedures used to assure that potted plants do not contain fire ants are relatively expensive and time consuming.

[0004] Similarly, intrusions by spiders of houses often produce unsightly webs which may be difficult to reach and eliminate.

[0005] In some areas, cold blooded animal other than insects create problems. For example, the brown tree snake, a venomous constrictor is a problem in the Pacific Islands, such as Guam and Hawaii where they frequently invade homes in search of food. Their control has been limited because of the collateral impact any effective control, would have on the endangered species.

[0006] Finally, crawling insects and soil borne insects can destroy crops and can create a nuisance and damage living areas.

SUMMARY OF THE INVENTION

[0007] Controlled release devices are shaped and placed in locations through which insects and/or other cold blooded animals generally enter an area or a structure sought to be protected. For the devices to be effective the release rate of the pesticide must be at least 10 μg/cm²/day for insects and must be at least 40μg/cm²/day for cold blooded vertebrae animals. The controlled release devices include a polymeric matrix and a pesticide contained in the matrix. The pesticide is gradually released out of the matrix to the surface of the device. The pesticide on the surface of the device kills the intruding insects or other cold blooded animals that come into contact with the pesticide. In addition, if the device is in contact with a permeable structure or object, the pesticide released onto the surface of the device is absorbed by such permeable structure or object to provide a barrier to entry by the insects and/or other cold blooded animals. The pesticides that have been found useful in connection with the present invention include pyrethrins and fenoxycarb. The polymeric matrices can be made from any polymer which provides desired release rates and incorporates the pesticide without effecting its pesticidal activity. The preferred polymers include silicones, EVA, urethanes, polyurethanes, acrylonitrile butadene, acrylic rubber, ois isoprene and styrene-vinyl rubber.

[0008] The present invention is particularly useful in preventing intrusions by fire ants, spiders, crawling insects and other cold blooded animals such as snakes and lizards.

DETAILED DESCRIPTION

[0009] It has been discovered that controlled release devices which gradually release pesticides can be constructed to prevent, for a prolonged period of time, intrusions by insects and/or other cold blooded animals into areas, structures or objects that are sought to be protected from intrusions. The protection offered by the controlled release devices constructed and used in accordance with the present invention generally lasts from about 6 months to about 5 years.

[0010] Any polymer which can provide the desired release rate and which does not destroy the pesticidal nature of the pesticide used in the device can be employed to provide a polymeric in accordance with the present invention. Generally, suitable polymers can include both thermoset and thermoplastic polymers. Currently preferred polymers are silicones, urethanes, polyurethanes, acrylonitrile butadiene, acrylic rubber, styrene-vinyl rubber EVA and polyethylenes. Especially preferred are the following polymers: RTV-41, Hytrel, Solithane, Nipol 1312, Nipol 1312 LV, Hycar X16, Kraton D1101, Ultra Clear, Aromatic 80A urethane, Pellethane 2102-80A, Pellethane 2102-55D Alipmtic PS-49-100, Polyurethane 3100, Polyurethane 2200, EVA 763, Polyethylene MA 7800, and Polyethylene MA 78000.

[0011] Pesticides that can be employed in the matrices of the present invention include those that provide desired release rates at least about 10μg/cm²/day for insects and at least about 40μg/cm2/day for cold blooded vertebras can be incorporated into a polymeric matrix and whose matricidal quality is not destroyed by incorporation in the matrix. The concentration of the pesticide in the matrix is generally in the range from about 2 to about 15 percent of the total weight of he matrix and preferably in the range from about 5 to about 10 percent.

[0012] In some control release devices of the present invention a carrier can be included to produce a desired release rate. A carrier can be carbon black clay or amorphous silica. Carbon black is currently preferred. The concentration of the carrier can range from about 2 to about 5 percent per total weight of the matrix, preferably it is in the range from about 3 to about 5 percent.

[0013] A description of general principles of making controlled release devices is given in U.S. patent application Ser. Nos. 06/555,113 filed Nov. 23, 1983 which is a continuation in part of 06/314,809 and 06/314,810 both filed on Oct. 26, 1981; 07/086,757, filed Aug. 18, 1987, 07/072,080 filed Jul. 10, 1987; and 07/091,918 filed Sep. 1, 1987. Methods for obtaining the release rates are described in patent application 07/303,707 filed on Jan. 30, 1989. The contents of these applications are being incorporated herein by reference.

[0014] The protection against intrusion is provided by the present invention as the result of the accumulation of the pesticide on the surface of the polymer matrix and/or the accumulation of the pesticide in an absorbent medium in contact with or in close proximity to the matrix, when the insect or other cold blooded animal comes in contact with pesticide it is repelled by it and/or killed by it. In case of insects, the pesticide is generally transferred to the feet of the insects and when the release rate of the pesticide is at least about 10μg/cm2/day, sufficient amount of pesticide adheres to insect to kill it. It has been discovered that faster release rates are necessary for larger cold blooded animals. For snakes, and other cold blooded vertebrae animals, the pesticide release rates must be at least 40μg/cm2/day.

EXAMPLE

[0015] The following controlled release devices were made and tested to obtain their release rates. The devices were made as follows. All devices, except for those employing S-113 urethane, were injection molded into a thin sheet about ⅛ inch thick. The device employing S-113 urethane was cast, a method typically used for thermoset polymers. All thermoplastics were formulated using sufficient amount of carbon black to carry pesticides. All thermoplastic polymers were formulated with 10 percent pesticide, 3 or 7 percent carbon black to absorb liquid pesticide and 87 to 83 percent by weight of polymer. Specifically, devices made from thermoplastic polymers and deltamethrin and lambdacyhalothrin contained 3 percent of carbon black. The devices made from the remaining pesticides and thermoplastic polymers contained 7 percent of carbon black.

[0016] The devices made from S-113 urethane (a thermoset polymer) were made from a polymer mix containing 60% S- 113, 40% castor oil and 5% of TIPA catalyst by weight. The polymer mix comprised 90% of the total weight of the device. The pesticide, deltamethrin, comprised the remaining 10% of the device. No carbon black was used in this device. The polymer/pesticide mixture was cast, using a spin caster into a ⅛ inch thick sheet and heated at about 60° C. for about 40 to 60 minutes to cure the cast sheet.

[0017] On inch squares were then cut from the thin sheets that were injection molded or cast and the squares were tested for release rates. The following release rates were obtained: Pesticide Polymer Release Rate Deltamethrin S-113 urethane 25.2 μg/cm2/day  Aromatic 80A 16.8 μg/cm2/day  pellethane 2102-80A 8.8 μg/cm2/day pellethane 2102-55D 8.0 μg/cm2/day Alipmtic PS-49-100 7.2 μg/cm2/day Cypermethrin polyurethane 3100 0.4 μg/cm2/day polyurethane 2200 0.7 μg/cm2/day EVA 763 27.3 μg/cm2/day  Polyethylene MA7800 4.6 μg/cm2/day Lambdacyhalothrin polyurethane 3100 0.7 μg/cm2/day polyurethane 2200 2.0 μg/cm2/day EVA 763 20.6 μg/cm2/day  Polyethylene MA78000 5.2 μg/cm2/day Tefluthrin polyurethane 3100 6.4 μg/cm2/day polyurethane 2200 25.0 μg/cm2/day  EVA 763 40.4 μg/cm2/day  polyethylene MA78000 27.0 μg/cm2/day  Permethrin polyurethane 3100 1.4 μg/cm2/day polyurethane 2200 1.3 μg/cm2/day EVA 763 28.5 μg/cm2/day  Polyethylene MA78000 4.0 μg/cm2/day

[0018] From the foregoing description one skilled in the art can easily ascertain the essential characteristics of this invention and without department from the spirit and scope of the invention thereof can make changes and modifications of the invention in order to adapt it to the various usages and conditions. It is intended that the scope of the invention be defined by the following claims including all equivalents. 

Claims:
 1. A system for providing long-term protection of an area or a structure from intrusion by crawling or soil borne insects, said system comprising: a controlled release barrier placed at the entry points to said area or said structure, said barrier comprising: 78-98 weight percent of polymeric matrix having an outside surface; 2-15 percent of pesticide, said pesticide being dispersed throughout said matrix; 0-7 percent by weight of a carrier, said pesticide releasing to the surface at a rate of least about 10 μg/cm²/day so as to repel or kill said crawling or soil borne insects coming in contact with the surface of the barrier.
 2. The system of claim 1 wherein the polymeric matrix is selected from a group consisting of silicones, EVA, urethanes, polyurethanes, acrylonitrile, butadiene, acrylic rubber, isoprene and styrene-vinyl rubber.
 3. The system of claim 2 wherein the polymeric matrix further includes a carrier for controlling the release rate.
 4. The system of claim 3 wherein the carrier is selected from the group consisting of carbon black, clay or amorphous silica.
 5. The system of claim 4 wherein the carrier is carbon black.
 6. The system of claim 2 wherein the concentration of the carrier is from about 2 to about 7 percent of the total weight of the system.
 7. The system of claim 4 wherein the concentration of the carrier is from about 3 to about 5 percent of the total weight of the system.
 8. The system of claim 1 wherein the concentration of the pesticide is in the range from about 2 to about 15 percent of the total weight of the system.
 9. The system of claim 3 wherein the concentration of pesticide is from about 5 to about 10 percent of the total weight of the system.
 10. The system of claim 8 wherein the pesticide is deltamethrin.
 11. The system of claim 8 wherein the pesticide is cypermethrin.
 12. The system of claim 8 wherein the pesticide is lamdacyhalothrin.
 13. The system of claim 8 wherein the pesticide is tefluthrin.
 14. The system of claim 8 wherein the pesticide is permethrin.
 15. The system of claim 1 wherein the system is large enough to continue releasing the pesticide at a rate above 10 μg/cm²/day for a time period from about 6 months to 5 years.
 16. A system for providing long-term protection of an area or a structure from intrusion by cold-blooded vertebrae animals, said system comprising: 78-98 weight percent of polymeric matrix having an outside surface; 2-15 percent of pesticide, said pesticide being dispersed throughout said matrix; 0-7 percent by weight of a carrier, said pesticide releasing to the surface at a rate of least about 40 μg/cm²/day so as to repel or kill insects coming in contact with the surface of the system.
 17. The system of claim 16 wherein the polymeric matrix is selected from a group consisting of silicones, EVA, urethanes, polyurethanes, acrylonitrile, butadene, acrylic rubber, isoprene and styrene-vinyl rubber.
 18. The system of claim 17 wherein the polymeric matrix further includes a carrier for controlling the release rate.
 19. The system of claim 18 wherein the carrier is selected from the group consisting of carbon black, clay or amorphous silica.
 20. The system of claim 19 wherein the carrier is carbon black.
 21. The system of claim 17 wherein the concentration of the carrier is from about 2 to about 7 percent of the total weight of the system.
 22. The system of claim 19 wherein the concentration of the carrier is from about 3 to about 5 percent of the total weight of the system.
 23. The system of claim 16 wherein the concentration of the pesticide is in the range from about 2 to about 15 percent of the total weight of the system.
 24. The system of claim 18 wherein the concentration of pesticide is from about 5 to about 10 percent of the total weight of the matrix.
 25. The system of claim 23 wherein the pesticide is deltamethrin.
 26. The system of claim 23 wherein the pesticide is cypermethrin.
 27. The system of claim 23 wherein the pesticide is lamdacyhalothrin.
 28. The system of claim 23 wherein the pesticide is tefluthrin.
 29. The system of claim 23 wherein the pesticide is permethrin.
 30. The system of claim 16 wherein the system is large enough to continue releasing the pesticide at a rate above 10 μg/cm²/day for a time period from about 6 months to 5 years. 